1. Field of the Invention
The present invention relates to a tunnel service system enabling data communication between different types of networks, and more particularly, to a tunnel service system capable of more easily setting an address of a tunnel router providing a tunnel service to a user node.
2. Description of the Related Art
In order to improve the conventional Internet protocol version 4 (IPv4), Internet protocol version 6 (IPv6) is being developed. IPv6 is also referred to as a next generation IP.
One of major characteristics of the IPv6 is that the length of an IP address is extended to 128 bits from the conventional 32 bits to prevent a possible shortage of IP addresses with the rapid growth of the Internet. Also, with the extension of a header area, the IPv6 allows designation of a mechanism for authentication of the source of a packet, guaranteeing data integrity, and guaranteeing security.
FIG. 1 is a schematic diagram of a conventional tunnel service providing system. Any of a user node 110 and a destination node 160 shown in FIG. 1 is a node having the IPv6 function, and is a mobile node such as a notebook computer or a personal digital assistant (PDA), or a non-mobile node with a fixed location such as a desktop computer.
In order for the user node 110 located on a first IPv6 network 100 to transmit a packet to the destination node 160 located on a second IPv6 network 150 through an IPv4 network 130, a tunnel between the user node 110 and the destination node 160 should be established. Establishing a tunnel between the user node 110 and the destination node 160 is referred to as a tunnel service. The tunnel service is provided to transmit an IPv6 packet generated by the user node 110 supporting the IPv6 to the destination node 160 through the IPv4 network.
More specifically, an IPv6 packet generated by the user node 110 is transmitted to a first tunnel router 120. The first tunnel router 120 encapsulates the received IPv6 packet so that the packet can be transmitted to the destination node 160 through the IPv4 network 130.
FIG. 2 is a diagram showing a conventional encapsulation process. Referring to FIG. 2, the IPv6 packet 180 includes the address of the destination node 160 that is the destination address, the address of the user node 110 that is the home address where the packet is generated, and data. In order to transmit the IPv6 packet 180 to the destination node 160 through the IPv4 network 130 and a second tunnel router 140, the first tunnel router 120 generates an IPv4 packet 190 by adding addresses of the second tunnel router 140 and the first tunnel router 120, having an IP address format complying with IPv4, to the IPv6 packet 180. This process is referred to as encapsulation and the inverse process is referred to as decapsulation. The IPv4 packet 190 is decapsulated by the second tunnel router 140 and then is transmitted to the destination node 160.
According to the conventional technology, the address of the first tunnel router 120 providing a tunnel service should be directly set in the user node 110.
In addition, when the address of the first tunnel router 120 changes or a new tunnel router is installed, the user should directly set the changed or new tunnel router address in the user node.